This invention is related generally to lenticular lenses and bar codes. In one aspect, the invention relates to a lenticular bar code image. In another aspect, the invention relates to methods of using and making the lenticular bar code image such that the bar code can be successfully scanned through the lenticular lens.
Lenticular Lenses and Lenticular Imaging
Lenticular lenses are found to be an effective way to create multidimensional effects from two-dimensional printed images. Lenticular lenses take the form of a transparent plastic sheet or web, and the sheet typically includes an array of identical curved or ribbed surfaces that are formed (e.g., cast, coated, embossed, extruded, or co-extruded) on the front surface of the plastic sheet. The back surface of the lens is typically flat. Each lenticule or individual lens is typically a section of a long cylinder that focuses on, and extends over, substantially the full length of an underlying image. Other lens shapes or profiles are possible (for instance, pyramidal, trapezoidal, parabolic, and the like). The lenticular lens is generally selected to accommodate both the underlying image and the distance from which the image will ordinarily be viewed. Methods for using lenticular lens technology are described in detail in U.S. Pat. Nos. 5,113,213 and 5,266,995, the teachings and disclosures of which are incorporated here by reference.
A lenticular image comprises an underlying precursor image that has been applied to a lenticular lens. The precursor image is a composite of two or more component images that are themselves preferably of photographic quality. The component images are selected based upon the desired features of the lenticular or final image. The component images are then arranged and/or segmented to create the precursor image so that the precursor image (or simply “image”) corresponds with the lenticular lens in any convenient manner, e.g., such as those taught in U.S. Pat. Nos. 5,488,451; 5,617,178; 5,847,808; and 5,896,230, the teachings and disclosures of which are incorporated here by reference.
Preferably, the image is printed directly to the flat back surface of the lenticular sheet or film, e.g., as taught in U.S. Pat. No. 5,457,515, the teachings and disclosures of which are incorporated here by reference.
As one example, lenticular lenses having ribbed lenticules with widths on the order of about 0.01333 inches (corresponding to a lenticular lens having about 75 lenticules per inch or “LPI”) have been used in the printing industry, and in particular, for lithographically printed applications Lenses having lenticules of such widths are considered to be “coarse” in their resolution and, as such, they typically cannot resolve small print or thin lines. Rather, resolving small type/font sizes requires a more “fine” lens resolution, namely, lenses having lenticules with widths on the order of about 0.006667 inches, more preferably about 0.005000 inches, and most preferably about 0.003333 inches or less. Such lenses are termed “high resolution” lenses. One example of a high definition lens is described in U.S. patent application Ser. No. 09/816,435, now U.S. Pat. No. 6,424,467, issued Jul. 23, 2002, entitled “High Definition Lenticular Lens,”the teachings and disclosures of which are incorporated herein by reference.
Today, lenticular technology is in use on a variety of items, such as: promotional buttons, magnets, coasters, collectibles, display posters, signs, menu boards, postcards and business cards. Lenticular technology is also used in packaging, publishing and labeling applications. Such applications often include areas that contain small fonts and/or fine seraphs having type sizes, on the order of about nine (9) points or less. Warning labels, ingredient labels or listings, and ownership or attribution markings (e.g., “© 2001 National Graphics, Inc., All Rights Reserved”), and the like are instances where small type size is common. As used herein, “resolve” means to make visible and distinguish parts of an image. Issues like these have posed problems for those attempting to use lenticular technology in conjunction with packaging, publishing, labeling and other applications.
Bar Codes
In addition, bar code symbols comprising lines and spaces between the lines have also proven difficult to resolve. A bar code symbol is a coded pattern of indicia comprised of a series of bars of various widths spaced apart from one another to bound spaces of various widths, the bars and spaces having different light reflecting characteristics.
The bars of bar code symbols are typically rectangular in shape. The bars or elements typically have a variety of possible widths. The specific arrangement of elements defines a character that can be represented according to a set of rules and definitions specified by the code or “symbology” that is used. The relative size of the bars and spaces between the bars is determined by the type of coding used, as is the actual size of the bars and spaces. The number of characters (represented by the bar code symbol) is referred to as the density of the symbol. To encode a desired sequence of the characters, a collection of element arrangements are concatenated together to form a complete bar code symbol, with each character of the message being represented by its own corresponding group of elements. In some symbologies, a unique “start” and “stop” character is used to indicate when the bar code begins and ends. A number of different bar code symbologies exist, these symbologies can include, for example, UPC/EAN, Code 39, Code 128, Codeabar, Interleaved 2 of 5, etc.
When using bar code symbologies, it is imperative that the bar code symbols be successfully read. Various optical readers and optical scanning systems have been developed previously to successfully read indicia such as bar code symbols. Bar code symbols typically appear on a label or on a surface of an article, for example, a package or other product. The readers in scanning systems electro-optically transform the graphic indicia into electrical signals, which are then decoded into alpha numeric characters that are intended to be descriptive of the article or some characteristic thereof. Such characteristics are typically represented in digital form and utilized as an input to a data processing system for applications in point-of-sale processing, inventory control and the like. Scanning systems in general have been disclosed, for example, in U.S. Pat. No. 4,896,026. One embodiment of such a scanning system resides, in a hand-held portable laser scanning device supported by a user, which is configured to allow the user to aim the scanning head of the device, and more particularly, a light beam, at a targeted symbol so as to be read successfully.
In order to determine bar code quality, it is important to note that even slight variations in bar code thickness or the absence of spaces between the bars, or elimination of entire bars, can substantially impact the ability of the bar code symbol to be properly scanned and that, once scanned, return the information corresponding to the particular bar code symbol. Therefore, even if the bar code may “appear” correct, slight variations in the bar code may still exist. The importance of successful scanning is emphasized particularly when it is desired to print the bar code image to a lenticular, which in general provides for multi-dimensional effects upon the image that is joined to the lenticular lens. In fact, in the commercial industry, some retailers institute fines or charge-backs when the bar code symbol is not able to be properly scanned, or results in mis-scanning. Therefore, bar code symbol readability is an extremely important issue.
Bar code symbols generally encode data in much the same way that Morse Code works, in that the alternation of wide and narrow bars and spaces is used to define particular characters. The widths of the bars and the spaces are critical. If the widths are not correct, the bar code could be unreadable or could be decoded improperly. In addition, the contrast between the bars and spaces must be sufficient enough that the bar code reader is able to distinguish between the two. Additionally, bar codes generally have quiet zones on either side of the bar code symbol. These are blank areas which do not have any printing and are typically ten times the width of the narrowest bar or space in the bar code.
Printed images are ubiquitous in commercial applications, such as labels, packages, cups, and the like. When it is desired to utilize a bar code, it is useful to have the bar codes incorporated into the printed image, as opposed to post printing application of the bar code to the image. Such printing processes generally require fewer manufacturing operations and are, by and large, less expensive. In this way, the bar code does not have to be printed separately from the printed image(s). For those applications in which a lenticular effect is desired for the printed image, the printed image is joined to, so as to be viewed through, the lenticular lens. The lenticular lens overlays the image. Consequently, when the image includes a bar code, the lenticular lens overlays the bar code as well.
However, in scanning bar codes that have been joined to lenticular lenses, problems have occurred that diminish the percentage of successful read rates of the bar codes. More specifically, it has been found that the lenticular lenses can distort the bar code image that is to be read by a bar code scanner, because of, for example, the shape of the particular lenticules, or the thickness of the lens material itself.
Accordingly, it is desirable to be able to join a bar code image directly to the lenticular lens, and yet maintain the functionality and readability of the bar code image when it is scanned through the lens.